Effects of continuous sulfamonomethoxine shock on the power generation performance and microbial community structure of MFCs under seasonal temperature variation

Abstract Sulfamonomethoxine (SMM) has become a high-priority emerging pollutant due to its wide application and environmental risks. This study assessed the effect of SMM shock on the power generation performance and microbial community structure of microbial fuel cells (MFCs) under seasonal temperature variation. Stable voltage could be obtained in the range of 13―33 °C without SMM addition (B-MFC), but dramatically decreased voltage was observed below 13 °C. Power generation was adversely affected by the addition of 4 mg L―1 SMM (S-MFC), but gradually increased with extended operation. Furthermore, the addition of SMM aggravated the effect of low temperature on S-MFC, and it took longer for the voltage to stabilize compared within the B-MFC. 92.83 ± 1.54 % of SMM (10 mg L―1) could be degraded by S-MFC, and the inhibitory effect of effluent on Escherichia coli and Bacillus subtilis was almost eliminated. High-throughput sequencing demonstrated that the addition of SMM drove a shift in the anodic microbial community from electroactive bacteria such as Spirochaetaceae, Petrimonas, Acidovorax, and Geobacter to bacteria with dual functions of electricity generation and SMM degradation, including Cupriavidus, Rhodococcus, Sphaerochaeta, and Cloacibacillus. PICRUSt functional prediction results further confirmed that the relative abundance of cellular processing and genetic information processing functions was enhanced in B-MFC, while biodegradation and metabolism functional groups accumulated in S-MFC.